1022 строки
24 KiB
C
1022 строки
24 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <linux/filter.h>
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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#include "bpf_rlimit.h"
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#include "bpf_util.h"
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#include "cgroup_helpers.h"
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#define CG_PATH "/sockopt"
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static char bpf_log_buf[4096];
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static bool verbose;
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enum sockopt_test_error {
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OK = 0,
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DENY_LOAD,
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DENY_ATTACH,
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EPERM_GETSOCKOPT,
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EFAULT_GETSOCKOPT,
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EPERM_SETSOCKOPT,
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EFAULT_SETSOCKOPT,
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};
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static struct sockopt_test {
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const char *descr;
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const struct bpf_insn insns[64];
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enum bpf_attach_type attach_type;
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enum bpf_attach_type expected_attach_type;
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int set_optname;
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int set_level;
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const char set_optval[64];
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socklen_t set_optlen;
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int get_optname;
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int get_level;
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const char get_optval[64];
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socklen_t get_optlen;
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socklen_t get_optlen_ret;
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enum sockopt_test_error error;
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} tests[] = {
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/* ==================== getsockopt ==================== */
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{
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.descr = "getsockopt: no expected_attach_type",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = 0,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: wrong expected_attach_type",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
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.error = DENY_ATTACH,
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},
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{
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.descr = "getsockopt: bypass bpf hook",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_level = SOL_IP,
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.set_level = SOL_IP,
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.get_optname = IP_TOS,
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.set_optname = IP_TOS,
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.set_optval = { 1 << 3 },
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.set_optlen = 1,
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.get_optval = { 1 << 3 },
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.get_optlen = 1,
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},
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{
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.descr = "getsockopt: return EPERM from bpf hook",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_level = SOL_IP,
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.get_optname = IP_TOS,
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.get_optlen = 1,
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.error = EPERM_GETSOCKOPT,
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},
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{
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.descr = "getsockopt: no optval bounds check, deny loading",
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.insns = {
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/* r6 = ctx->optval */
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BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, optval)),
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/* ctx->optval[0] = 0x80 */
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BPF_MOV64_IMM(BPF_REG_0, 0x80),
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BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_0, 0),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: read ctx->level",
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.insns = {
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/* r6 = ctx->level */
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BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, level)),
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/* if (ctx->level == 123) { */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_JMP_A(1),
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/* } else { */
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/* return 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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/* } */
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_level = 123,
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.get_optlen = 1,
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},
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{
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.descr = "getsockopt: deny writing to ctx->level",
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.insns = {
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/* ctx->level = 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, level)),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: read ctx->optname",
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.insns = {
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/* r6 = ctx->optname */
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BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, optname)),
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/* if (ctx->optname == 123) { */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_JMP_A(1),
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/* } else { */
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/* return 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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/* } */
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_optname = 123,
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.get_optlen = 1,
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},
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{
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.descr = "getsockopt: read ctx->retval",
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.insns = {
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/* r6 = ctx->retval */
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BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_level = SOL_IP,
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.get_optname = IP_TOS,
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.get_optlen = 1,
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},
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{
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.descr = "getsockopt: deny writing to ctx->optname",
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.insns = {
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/* ctx->optname = 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, optname)),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: read ctx->optlen",
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.insns = {
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/* r6 = ctx->optlen */
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BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, optlen)),
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/* if (ctx->optlen == 64) { */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_JMP_A(1),
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/* } else { */
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/* return 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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/* } */
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_optlen = 64,
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},
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{
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.descr = "getsockopt: deny bigger ctx->optlen",
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.insns = {
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/* ctx->optlen = 65 */
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BPF_MOV64_IMM(BPF_REG_0, 65),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, optlen)),
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_optlen = 64,
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.error = EFAULT_GETSOCKOPT,
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},
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{
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.descr = "getsockopt: deny arbitrary ctx->retval",
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.insns = {
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/* ctx->retval = 123 */
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BPF_MOV64_IMM(BPF_REG_0, 123),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_optlen = 64,
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.error = EFAULT_GETSOCKOPT,
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},
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{
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.descr = "getsockopt: support smaller ctx->optlen",
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.insns = {
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/* ctx->optlen = 32 */
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BPF_MOV64_IMM(BPF_REG_0, 32),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, optlen)),
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_optlen = 64,
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.get_optlen_ret = 32,
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},
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{
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.descr = "getsockopt: deny writing to ctx->optval",
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.insns = {
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/* ctx->optval = 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, optval)),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: deny writing to ctx->optval_end",
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.insns = {
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/* ctx->optval_end = 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, optval_end)),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "getsockopt: rewrite value",
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.insns = {
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/* r6 = ctx->optval */
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BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, optval)),
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/* r2 = ctx->optval */
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BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
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/* r6 = ctx->optval + 1 */
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
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/* r7 = ctx->optval_end */
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BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
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offsetof(struct bpf_sockopt, optval_end)),
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/* if (ctx->optval + 1 <= ctx->optval_end) { */
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BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
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/* ctx->optval[0] = 0xF0 */
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BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 0xF0),
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/* } */
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/* ctx->retval = 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
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offsetof(struct bpf_sockopt, retval)),
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/* return 1*/
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_GETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.get_level = SOL_IP,
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.get_optname = IP_TOS,
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.get_optval = { 0xF0 },
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.get_optlen = 1,
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},
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/* ==================== setsockopt ==================== */
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{
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.descr = "setsockopt: no expected_attach_type",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_SETSOCKOPT,
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.expected_attach_type = 0,
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.error = DENY_LOAD,
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},
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{
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.descr = "setsockopt: wrong expected_attach_type",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_SETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
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.error = DENY_ATTACH,
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},
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{
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.descr = "setsockopt: bypass bpf hook",
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.insns = {
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_SETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
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.get_level = SOL_IP,
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.set_level = SOL_IP,
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.get_optname = IP_TOS,
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.set_optname = IP_TOS,
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.set_optval = { 1 << 3 },
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.set_optlen = 1,
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.get_optval = { 1 << 3 },
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.get_optlen = 1,
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},
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{
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.descr = "setsockopt: return EPERM from bpf hook",
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.insns = {
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/* return 0 */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_SETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
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.set_level = SOL_IP,
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.set_optname = IP_TOS,
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.set_optlen = 1,
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.error = EPERM_SETSOCKOPT,
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},
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{
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.descr = "setsockopt: no optval bounds check, deny loading",
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.insns = {
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/* r6 = ctx->optval */
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BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, optval)),
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/* r0 = ctx->optval[0] */
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, 0),
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/* return 1 */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.attach_type = BPF_CGROUP_SETSOCKOPT,
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.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
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.error = DENY_LOAD,
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},
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{
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.descr = "setsockopt: read ctx->level",
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.insns = {
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/* r6 = ctx->level */
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BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
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offsetof(struct bpf_sockopt, level)),
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/* if (ctx->level == 123) { */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
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/* ctx->optlen = -1 */
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BPF_MOV64_IMM(BPF_REG_0, -1),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_JMP_A(1),
|
|
/* } else { */
|
|
/* return 0 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* } */
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_level = 123,
|
|
|
|
.set_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: allow changing ctx->level",
|
|
.insns = {
|
|
/* ctx->level = SOL_IP */
|
|
BPF_MOV64_IMM(BPF_REG_0, SOL_IP),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, level)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.get_level = SOL_IP,
|
|
.set_level = 234, /* should be rewritten to SOL_IP */
|
|
|
|
.get_optname = IP_TOS,
|
|
.set_optname = IP_TOS,
|
|
|
|
.set_optval = { 1 << 3 },
|
|
.set_optlen = 1,
|
|
.get_optval = { 1 << 3 },
|
|
.get_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: read ctx->optname",
|
|
.insns = {
|
|
/* r6 = ctx->optname */
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optname)),
|
|
|
|
/* if (ctx->optname == 123) { */
|
|
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
|
|
/* ctx->optlen = -1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, -1),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_JMP_A(1),
|
|
/* } else { */
|
|
/* return 0 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* } */
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_optname = 123,
|
|
|
|
.set_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: allow changing ctx->optname",
|
|
.insns = {
|
|
/* ctx->optname = IP_TOS */
|
|
BPF_MOV64_IMM(BPF_REG_0, IP_TOS),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optname)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.get_level = SOL_IP,
|
|
.set_level = SOL_IP,
|
|
|
|
.get_optname = IP_TOS,
|
|
.set_optname = 456, /* should be rewritten to IP_TOS */
|
|
|
|
.set_optval = { 1 << 3 },
|
|
.set_optlen = 1,
|
|
.get_optval = { 1 << 3 },
|
|
.get_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: read ctx->optlen",
|
|
.insns = {
|
|
/* r6 = ctx->optlen */
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
|
|
/* if (ctx->optlen == 64) { */
|
|
BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
|
|
/* ctx->optlen = -1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, -1),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_JMP_A(1),
|
|
/* } else { */
|
|
/* return 0 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* } */
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_optlen = 64,
|
|
},
|
|
{
|
|
.descr = "setsockopt: ctx->optlen == -1 is ok",
|
|
.insns = {
|
|
/* ctx->optlen = -1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, -1),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_optlen = 64,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny ctx->optlen < 0 (except -1)",
|
|
.insns = {
|
|
/* ctx->optlen = -2 */
|
|
BPF_MOV64_IMM(BPF_REG_0, -2),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_optlen = 4,
|
|
|
|
.error = EFAULT_SETSOCKOPT,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny ctx->optlen > input optlen",
|
|
.insns = {
|
|
/* ctx->optlen = 65 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 65),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.set_optlen = 64,
|
|
|
|
.error = EFAULT_SETSOCKOPT,
|
|
},
|
|
{
|
|
.descr = "setsockopt: allow changing ctx->optlen within bounds",
|
|
.insns = {
|
|
/* r6 = ctx->optval */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval)),
|
|
/* r2 = ctx->optval */
|
|
BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
|
|
/* r6 = ctx->optval + 1 */
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
|
|
|
|
/* r7 = ctx->optval_end */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval_end)),
|
|
|
|
/* if (ctx->optval + 1 <= ctx->optval_end) { */
|
|
BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
|
|
/* ctx->optval[0] = 1 << 3 */
|
|
BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 1 << 3),
|
|
/* } */
|
|
|
|
/* ctx->optlen = 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optlen)),
|
|
|
|
/* return 1*/
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.get_level = SOL_IP,
|
|
.set_level = SOL_IP,
|
|
|
|
.get_optname = IP_TOS,
|
|
.set_optname = IP_TOS,
|
|
|
|
.set_optval = { 1, 1, 1, 1 },
|
|
.set_optlen = 4,
|
|
.get_optval = { 1 << 3 },
|
|
.get_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny write ctx->retval",
|
|
.insns = {
|
|
/* ctx->retval = 0 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, retval)),
|
|
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.error = DENY_LOAD,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny read ctx->retval",
|
|
.insns = {
|
|
/* r6 = ctx->retval */
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, retval)),
|
|
|
|
/* return 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.error = DENY_LOAD,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny writing to ctx->optval",
|
|
.insns = {
|
|
/* ctx->optval = 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optval)),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.error = DENY_LOAD,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny writing to ctx->optval_end",
|
|
.insns = {
|
|
/* ctx->optval_end = 1 */
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
|
|
offsetof(struct bpf_sockopt, optval_end)),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.error = DENY_LOAD,
|
|
},
|
|
{
|
|
.descr = "setsockopt: allow IP_TOS <= 128",
|
|
.insns = {
|
|
/* r6 = ctx->optval */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval)),
|
|
/* r7 = ctx->optval + 1 */
|
|
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
|
|
|
|
/* r8 = ctx->optval_end */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval_end)),
|
|
|
|
/* if (ctx->optval + 1 <= ctx->optval_end) { */
|
|
BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
|
|
|
|
/* r9 = ctx->optval[0] */
|
|
BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
|
|
|
|
/* if (ctx->optval[0] < 128) */
|
|
BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_JMP_A(1),
|
|
/* } */
|
|
|
|
/* } else { */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* } */
|
|
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.get_level = SOL_IP,
|
|
.set_level = SOL_IP,
|
|
|
|
.get_optname = IP_TOS,
|
|
.set_optname = IP_TOS,
|
|
|
|
.set_optval = { 0x80 },
|
|
.set_optlen = 1,
|
|
.get_optval = { 0x80 },
|
|
.get_optlen = 1,
|
|
},
|
|
{
|
|
.descr = "setsockopt: deny IP_TOS > 128",
|
|
.insns = {
|
|
/* r6 = ctx->optval */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval)),
|
|
/* r7 = ctx->optval + 1 */
|
|
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
|
|
|
|
/* r8 = ctx->optval_end */
|
|
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
|
|
offsetof(struct bpf_sockopt, optval_end)),
|
|
|
|
/* if (ctx->optval + 1 <= ctx->optval_end) { */
|
|
BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
|
|
|
|
/* r9 = ctx->optval[0] */
|
|
BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
|
|
|
|
/* if (ctx->optval[0] < 128) */
|
|
BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
|
|
BPF_MOV64_IMM(BPF_REG_0, 1),
|
|
BPF_JMP_A(1),
|
|
/* } */
|
|
|
|
/* } else { */
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* } */
|
|
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
.expected_attach_type = BPF_CGROUP_SETSOCKOPT,
|
|
|
|
.get_level = SOL_IP,
|
|
.set_level = SOL_IP,
|
|
|
|
.get_optname = IP_TOS,
|
|
.set_optname = IP_TOS,
|
|
|
|
.set_optval = { 0x81 },
|
|
.set_optlen = 1,
|
|
.get_optval = { 0x00 },
|
|
.get_optlen = 1,
|
|
|
|
.error = EPERM_SETSOCKOPT,
|
|
},
|
|
};
|
|
|
|
static int load_prog(const struct bpf_insn *insns,
|
|
enum bpf_attach_type expected_attach_type)
|
|
{
|
|
struct bpf_load_program_attr attr = {
|
|
.prog_type = BPF_PROG_TYPE_CGROUP_SOCKOPT,
|
|
.expected_attach_type = expected_attach_type,
|
|
.insns = insns,
|
|
.license = "GPL",
|
|
.log_level = 2,
|
|
};
|
|
int fd;
|
|
|
|
for (;
|
|
insns[attr.insns_cnt].code != (BPF_JMP | BPF_EXIT);
|
|
attr.insns_cnt++) {
|
|
}
|
|
attr.insns_cnt++;
|
|
|
|
fd = bpf_load_program_xattr(&attr, bpf_log_buf, sizeof(bpf_log_buf));
|
|
if (verbose && fd < 0)
|
|
fprintf(stderr, "%s\n", bpf_log_buf);
|
|
|
|
return fd;
|
|
}
|
|
|
|
static int run_test(int cgroup_fd, struct sockopt_test *test)
|
|
{
|
|
int sock_fd, err, prog_fd;
|
|
void *optval = NULL;
|
|
int ret = 0;
|
|
|
|
prog_fd = load_prog(test->insns, test->expected_attach_type);
|
|
if (prog_fd < 0) {
|
|
if (test->error == DENY_LOAD)
|
|
return 0;
|
|
|
|
log_err("Failed to load BPF program");
|
|
return -1;
|
|
}
|
|
|
|
err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
|
|
if (err < 0) {
|
|
if (test->error == DENY_ATTACH)
|
|
goto close_prog_fd;
|
|
|
|
log_err("Failed to attach BPF program");
|
|
ret = -1;
|
|
goto close_prog_fd;
|
|
}
|
|
|
|
sock_fd = socket(AF_INET, SOCK_STREAM, 0);
|
|
if (sock_fd < 0) {
|
|
log_err("Failed to create AF_INET socket");
|
|
ret = -1;
|
|
goto detach_prog;
|
|
}
|
|
|
|
if (test->set_optlen) {
|
|
err = setsockopt(sock_fd, test->set_level, test->set_optname,
|
|
test->set_optval, test->set_optlen);
|
|
if (err) {
|
|
if (errno == EPERM && test->error == EPERM_SETSOCKOPT)
|
|
goto close_sock_fd;
|
|
if (errno == EFAULT && test->error == EFAULT_SETSOCKOPT)
|
|
goto free_optval;
|
|
|
|
log_err("Failed to call setsockopt");
|
|
ret = -1;
|
|
goto close_sock_fd;
|
|
}
|
|
}
|
|
|
|
if (test->get_optlen) {
|
|
optval = malloc(test->get_optlen);
|
|
socklen_t optlen = test->get_optlen;
|
|
socklen_t expected_get_optlen = test->get_optlen_ret ?:
|
|
test->get_optlen;
|
|
|
|
err = getsockopt(sock_fd, test->get_level, test->get_optname,
|
|
optval, &optlen);
|
|
if (err) {
|
|
if (errno == EPERM && test->error == EPERM_GETSOCKOPT)
|
|
goto free_optval;
|
|
if (errno == EFAULT && test->error == EFAULT_GETSOCKOPT)
|
|
goto free_optval;
|
|
|
|
log_err("Failed to call getsockopt");
|
|
ret = -1;
|
|
goto free_optval;
|
|
}
|
|
|
|
if (optlen != expected_get_optlen) {
|
|
errno = 0;
|
|
log_err("getsockopt returned unexpected optlen");
|
|
ret = -1;
|
|
goto free_optval;
|
|
}
|
|
|
|
if (memcmp(optval, test->get_optval, optlen) != 0) {
|
|
errno = 0;
|
|
log_err("getsockopt returned unexpected optval");
|
|
ret = -1;
|
|
goto free_optval;
|
|
}
|
|
}
|
|
|
|
ret = test->error != OK;
|
|
|
|
free_optval:
|
|
free(optval);
|
|
close_sock_fd:
|
|
close(sock_fd);
|
|
detach_prog:
|
|
bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
|
|
close_prog_fd:
|
|
close(prog_fd);
|
|
return ret;
|
|
}
|
|
|
|
int main(int args, char **argv)
|
|
{
|
|
int err = EXIT_FAILURE, error_cnt = 0;
|
|
int cgroup_fd, i;
|
|
|
|
if (setup_cgroup_environment())
|
|
goto cleanup_obj;
|
|
|
|
cgroup_fd = create_and_get_cgroup(CG_PATH);
|
|
if (cgroup_fd < 0)
|
|
goto cleanup_cgroup_env;
|
|
|
|
if (join_cgroup(CG_PATH))
|
|
goto cleanup_cgroup;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(tests); i++) {
|
|
int err = run_test(cgroup_fd, &tests[i]);
|
|
|
|
if (err)
|
|
error_cnt++;
|
|
|
|
printf("#%d %s: %s\n", i, err ? "FAIL" : "PASS",
|
|
tests[i].descr);
|
|
}
|
|
|
|
printf("Summary: %ld PASSED, %d FAILED\n",
|
|
ARRAY_SIZE(tests) - error_cnt, error_cnt);
|
|
err = error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
|
|
|
|
cleanup_cgroup:
|
|
close(cgroup_fd);
|
|
cleanup_cgroup_env:
|
|
cleanup_cgroup_environment();
|
|
cleanup_obj:
|
|
return err;
|
|
}
|